A stent refers to a tubular instrument that expands a stenosed site, etc., in order to secure a necessary lumen region when a blood vessel or a lumen inside a living organism is stenosed or occluded, which has a structure constituted by folding a small-gage wire of a metal, etc., in a zigzag form or rendering it network-structured and forming it into the form of a cylinder (tube).
A stent graft is an instrument obtained by applying a cylindrical structured body, composed, for example, of a polyester, etc., to an inside or outside of a cylindrical stent and suturing them together. This stent graft is inserted into a living body in a compressed state with a reduced diameter, and is delivered to a diseased site where aneurysm is developed, and is expanded at the diseased site in the radial direction and indwelled there, thus this stent graft constitutes a kind of artificial blood vessel and consequently can close said aneurysm and secure the bloodstream path.
As a indwelling device for placing a stent graft in a diseased site, conventionally, a stent graft indwelling device is known in which a front tip is provided in the forward end portion of a rod member (called pushing rod or dilator as well) (for example, see Patent Documents 1 to 3). In the front tip, there is formed a groove for hook engagement (hook engagement groove) that is engageable with a hook attached to the forward end portion of the stent graft.
According to the conventional stent graft indwelling device, the groove for the above hook engagement is formed in the front tip, so that the position of the indwelling site of the stent graft is determined while the hook and the groove are engaged with each other, and then the front tip is moved such that the engagement state is released, whereby the stent graft can be relatively easily placed in the intended position.